Local networks servicing a premise may provide for delivery of multimedia content over various mediums, such as one or more wireless channels. Multimedia content delivered over a wireless network can be particularly vulnerable to problems arising in the transmission of the content to a client device and in the processing of the content at the client device. For example, where multiple premises or devices are sharing the same wireless channel, one or more pieces of multimedia content may be streamed to a plurality of client devices at one time, and it is possible that network congestion can cause macro blocking or total audio/video delivery failure where packets are consumed by a device at a faster rate than the rate at which packets are received by the device.
Typically, one or more buffers are used at a client device to account for the non-deterministic rate at which packets are delivered to a client device from an access point or central device providing a wireless network. The one or more buffers can temporarily store packets as they are received from an access point, and the client device can read packets from the one or more buffers for decoding and output. The rate at which a buffer is filled may depend on a number of factors including the bandwidth available to a client device. It should be understood that buffer depth (i.e., size) may be different from one client device to the next.
Bandwidth allocated to a client device may depend on various factors, such as congestion of an associated wireless network, and an underflow condition may arise if the one or more buffers at a client device receive packets at a lower bit rate than the bit rate at which packets are read from the one or more buffers. For example, if a decoder is reading packets from a buffer at a faster rate than the rate at which packets are written into the buffer, the situation may arise where the buffer is emptied and the decoder has no packet to read from the buffer. An underflow condition can result in a stalled or fragmented picture in the output of the associated multimedia content. The rate at which packets are consumed by a client device may vary according to a number of factors including the type or quality of content received at the device (e.g., high-definition channels require more bandwidth than standard-definition channels).
Typically, a central device transmits packets evenly or at a common bitrate or quality of service to each of a plurality of client devices, and packet streams output to each of the plurality of client devices may be given the same priority level. However, client devices do not generally consume received packets at a constant or common bitrate, and one or more client devices within a group of client devices that are served by a common central device can become underserved or encounter an underflow event while other client devices within the group maintain a full or nearly full buffer. For example, a client device receiving a weak wireless signal from an access point may consume more airtime in receiving a given amount of data than client devices receiving a stronger wireless signal from the access point. Thus, the central device is unable to account for discrepancies in the quality of content delivery to multiple client devices sharing a quality of service (QoS) level. Therefore, a need exists for improving methods and systems for prioritizing packet delivery for one or more of a plurality of media streams.
Like reference numbers and designations in the various drawings indicate like elements.